论文部分内容阅读
为了研究后张法预应力超高性能钢纤维混凝土梁的受弯性能,对6根梁试件进行了3分点对称加载试验研究。试件变化参数包括非预应力纵筋强度等级、配筋率、张拉控制应力及预应力度,获得了试件的开裂弯矩、极限弯矩、破坏形态以及裂缝开展情况。试验结果表明:HRB500级钢筋与UHPSFC适配良好,可以充分发挥二者的高强性能;张拉控制应力及预应力度增加,开裂弯矩增大;高性能钢纤维混凝土梁弯曲裂缝细而密,正常使用极限状态下最大裂缝宽度不大于0.15 mm。通过引入抗裂影响系数对受拉区塑性影响系数进行修正后,开裂弯矩计算值与试验值吻合较好。根据简化的高性能钢纤维混凝土本构模型建立了高性能钢纤维混凝土梁的受弯承载力计算公式,其计算值与试验值吻合良好,可为高性能钢纤维混凝土梁理论分析和设计提供参考。
In order to study the flexural behavior of post-tensioned prestressed ultra-high-performance steel fiber reinforced concrete beams, three points symmetrical loading experiments were carried out on the six beams. The parameters of specimen include non-prestressed longitudinal reinforcement strength grade, reinforcement ratio, tension control stress and prestressing force. Cracking bending moment, ultimate bending moment, failure mode and crack initiation were obtained. The test results show that: HRB500 grade steel and UHPSFC well-fitted, you can give full play to the high strength performance of both; tension control and prestressed stress increases, cracking moment increases; high-performance steel fiber reinforced concrete beam bending crack thin and dense, The maximum crack width under normal use limit is not more than 0.15 mm. After introducing the influence coefficient of cracking resistance on the plasticity influence coefficient of tension zone, the calculated value of cracking moment is in good agreement with the experimental value. According to the simplified high performance steel fiber reinforced concrete constitutive model, the formula of flexural capacity of high performance steel fiber reinforced concrete beam is established. The calculated value is in good agreement with the experimental data, which can provide reference for theoretical analysis and design of high performance steel fiber reinforced concrete beam. .